This is a rare find, and a goodie in Star Trek Prop history. The "Photon Collector" that Chekov and Uhuru used in Star Trek IV is up for sale by a private collector. He has asked me to help him with the sale of it, and so here is some information. If you are interested, please email me at firstname.lastname@example.org. This is what the owner has to say:
Pictures: As seen on screen and as held by Koenig in 2003. The item has been in a display case since and has undergone no change in condition.
Condition: Paint job/overall condition - excellent.
Provenance: When this item went for auction, I contacted Richard Coyle to have him investigate whether it was in fact the screen-used hero he created. He checked out the auction and verified that it was. I have e-mail correspondence regarding the history of the prop and the "tells" Richard was relying on to verify it as the hero, as well as telephone conversation with Richard regarding the tells.
Richard also issued me a COA verifying the item (which I will give to the buyer).
As for how the item came "off the lot", Richard says (reflected in e-mails) that the item was used in the "nuclear wessel" scenes, then the request was made for him to take the hero unit used in those scenes and modify it as described above for later scenes on the Bird of Prey. He made these changes but was told the scene had been cut when he returned the item to the set. Richard then asked if he could keep the prop, and was told yes.
I am happy to provide any e-mails I can locate and/or to have Richard re-verify, though I think the COA speaks for itself.
ALL screen-seen lights on this prop WORK, I replaced the battery (there is a battery connector in each of the two cylinders) because the red LEDs were dimming, and ALL lights came on that are seen on screen.
There is more information available. Photos are below.